We all know that during pregnancy, a woman's body goes through a great deal of change hormonally and physiologically.  But did you know her eyes change as well?  Below are some of the most common effects pregnancy can have on the eye.

• Corneal changes. In some cases, pregnancy can cause the cornea, the front window of the eye, to change curvature and even swell, leading to shifts in glasses and contact lens prescriptions. In addition, changes in the chemistry of the tear film can lead to dry eyes and contact lens intolerance. It is for these reasons that it is generally not recommended to have any new contact lens fitting or new glasses prescription checks until several months postpartum. We want to get the most accurate measurements possible.
• Retinal changes.  Many different conditions can affect the retina during pregnancy. If the pregnant woman has diabetes, diabetic eye disease can progress by 50%. In women with preeclampsia, a condition where blood pressure rises significantly, over 40% of women can show changes in the retinal blood vessels, and 25% to 50% complain of changes to their vision.
• Eye Pressure Fluctuation.  Intraocular pressure (IOP) usually decreases during pregnancy. The exact mechanism causing this is unknown, but it is usually attributed to an increase of flow of intraocular fluid out of the eye. This is good news for pregnant women with glaucoma or high IOP. In fact, the drop in IOP is larger when you start with a high IOP compared to one in the normal range.

There are many more effects that pregnancy can have on the eye, but these are the most common. One other thing to keep in mind is that though the likelihood of any adverse effect is extremely low, we try not to use any diagnostic eye drops on pregnant patients during the eye exam. Unless there is a medical necessity to dilate the pupils or check IOP, it is a good rule of thumb to put off using drops until after the patient has given birth in order to protect the developing baby.